(a) Field of the Invention
A method of manufacturing nanoparticles, nanoparticles, and an organic light emitting diode, a solar cell, a printing ink, a bioimaging device, and a sensor including the same.
(b) Description of the Related Art
Recently, nanoparticles of a polymer or a metal oxide or the like have been widely used for an organic light emitting diode, a solar cell, a sensor, or the like. The nanoparticles need to be provided in an aqueous solution, and the conventional nanoparticle aqueous solution may be manufactured by miniemulsification, reprecipitation, or the like.
In the case of miniemulsification, a target material is dissolved in a hydrophobic organic solvent and then added to water including a surfactant. Then the target material forms nanoparticles according to ultrasonication, and the organic solvent is evaporated to provide a nanoparticle aqueous solution stabilized by the surfactant.
The surfactant does not affect the optical properties (UV-vis, PL spectrum) or the like of nanoparticles, but may deteriorate the electrical properties (exciton generation, migration, and recombination) or the like, so that application to the organic light emitting diode is limited.
The precipitation uses the phenomenon that the target material is aggregated in nanoparticles when the target material is dissolved in a polar organic solvent that is miscible with water and added to water. The nanoparticle obtained by precipitation has demerits of deteriorating the optical properties of nanoparticles since the target material is easily aggregated and the difficulty of controlling the nanoparticle size. In addition, the nanoparticle has narrow application fields since it is difficult to induce the functional group to the nanoparticle to apply the various functions.
Therefore, a method of manufacturing nanoparticles which may maintain the electrical characteristics while not deteriorating the optical characteristics of a target material and may apply the various functions to the target material is required.